---
title: "REV ION Build System — Team 2890 Structure"
tags:
  - hardware
  - structure
  - extrusion
  - REV
  - 2890
  - ion
type: hardware-spec
owner: 2890
status: active
sources:
  - "https://docs.revrobotics.com/ion-build"
  - "https://docs.revrobotics.com/ion-build/structure/extrusion"
growth: tree
---

# REV ION Build System — Structure & Extrusion

## Overview

Team 2890 uses the **REV ION Build System** as their primary mechanical structure system. ION is designed to enable rapid iteration and reconfiguration without large budgets or extensive manufacturing resources. The system is built around the **MAXSpline** — a unique spline shape that combines bearing support with torque transfer.

## Core Concepts

### MAXSpline

The MAXSpline is the foundation of the ION system. It appears in:
- MAX Hubs (for bearing and sprocket mounting)
- Live axle applications
- Motion components (linear slides, rotations)

The shape allows bearing support and torque transfer to be combined in a single feature — making mechanisms more compact.

### MAX Pattern

The MAX Pattern combines:
- **#10 clearance holes** in a 1/2" pitch grid
- **MAXSpline bore** every 2" down the length

This pattern enables:
- Easy bearing mounting with correct center-to-center distances
- 1:1 power transmission with #25 chain or RT25 belting
- Rapid prototyping with standard #10 hardware

### Grid Pattern

Some MAXTube features **three rows of #10 holes** on a 1/2" pitch grid. This is ideal for rapidly building structures with 1in brackets.

## MAXTube Extrusions

MAXTube is aluminum 6061 extrusion. Available sizes:

| Size | Pattern | Length | Nut Groove |
|------|---------|--------|------------|
| 1/2 × 1/2 in | Grid | 47in | No |
| 1 × 1 in | Grid | 47in | Yes |
| 1 × 1 in (1/16" wall) | Grid | 47in | No |
| 1 × 1 in (1/8" wall) | Grid | 47in | No |
| 2 × 1 in Light | No Pattern / Grid | 47in | Yes |
| 2 × 1 in | No Pattern / Grid / MAX | 3–47in | Yes |
| 2 × 2 in | Grid / MAX / MAX+Grid | 47in | No |

**Nut groove note:** On 1in sides, the nut groove holds #10 nuts in place where a wrench can't reach. Use **2×1 Standard** for secure bearing fit; **2×1 Light** where weight is critical.

## 1in Extrusion (REV-21-1000)

4-sided slot extrusion accepting standard #10 hardware including low-profile nylock nuts. No T-nut needed — slide #10 hex head through slot, adjust as needed. Can be tapped 10-32 for permanent mounting.

Good for builds that don't fit the standard pitch patterns.

## MAXSpline Bore Spacing

For proper chain alignment: center-to-center distances are set for simple 1:1 #25 chain transmission. The MAX Pattern bore spacing every 2in makes this straightforward.

## Connection to Training

**For students:** The ION system replaces custom machining. Understanding:
- **Why standardized patterns matter** — interchangeable parts, no custom drilling
- **MAXSpline as a system** — one spline shape across multiple components (hubs, bearings, motion)
- **Nut grooves eliminate blind assembly problems** — you can hold the nut while fastening
- **Pitch grid = predictable spacing** — 1/2in pitch means you always know where holes line up

**Related training modules:**
- [[swerving-modules]] — MK4i mounts to this structure
- [[motor-basics]] — how motors mount to structural extrusions
- [[frc-mechanical-basics]] — understanding structural systems

## Source Links

- ION Build overview: https://docs.revrobotics.com/ion-build
- Extrusion guide: https://docs.revrobotics.com/ion-build/structure/extrusion
- Product catalog: https://www.revrobotics.com/ion-system/

## Notes

Chris and team use this as their standard build system. The compatibility between ION mechanical and ION electrical (SPARK Flex, NEO Vortex) means the whole robot — structure, drivetrain, and motor control — uses one integrated system.